Client download pdf file using Response.BinaryWrite ASP.NET c#

Question

I'm trying to add a feature to download a pdf file. I'm using ironpdf to generate the pdf file and I want the user to click and download it.

Here is my handler.

try
        {
            // Render any HTML fragment or document to HTML
            var Renderer = new IronPdf.HtmlToPdf();
            var PDF = Renderer.RenderHtmlAsPdf("<h1>Hello IronPdf</h1>");
            var data = PDF.MetaData;
            context.Response.Clear();
            context.Response.ClearHeaders();
            context.Response.Buffer = true;
            context.Response.ContentType = "application/pdf";
            context.Response.AddHeader("content-disposition", "attachment;filename=Cotacao.pdf");
            context.Response.BinaryWrite(PDF.BinaryData);
            context.Response.Flush();
        }
        catch (Exception e)
        {

        }
        finally
        {
            context.ApplicationInstance.CompleteRequest();
        }

Here is my ajax request

function GeneratePDF() {
return $.ajax({
    type: "POST",
    url: "../Handlers/GeneratePDF.ashx",
    success: PDFSuccess,
    error: PDFError
});

I can see the output stream response in the browser but no download dialog. What am I doing wrong?

Thanks in advance.

Answer 1

I had the same issue, and was able to get it to work with FileDownload on the frontend:

const FileDownload = require('js-file-download');

postHtmlString(data).then(response => {
   console.log(response)
   commit('pdfDownloading', false)
   FileDownload(response.data, 'example.pdf');
})...

And my controller returns:

return File(pdf.BinaryData, "application/pdf");

Here is js-file-download: https://www.npmjs.com/package/js-file-download

Lastly, and maybe most importantly, you need to set the response type in your api request on the frontend:

 responseType: 'arraybuffer'